| The peak regulation balance is a necessary condition for the normal operation of the power system.Therefore,a reasonable and effective assessment of the peak regulation situation in the power system becomes one of the important tasks in power supply planning and power grid operation.However,in recent years,the continuous operation of UHVDC transmission lines based on renewable energy transmission,the continuous increase in the proportion of cogeneration units,and the rapid development of local renewable energy sources,will be a huge challenge to the balance of peak regulation of provincial power system,and traditional peak regulation assessment indicators and methods appear to be difficult to adapt.In order to make a comprehensive and accurate assessment of the future peak regulation situation under the new scenario,taking the provincial power grid as the research object,a new evaluation index is proposed for the new situation,and together with the original index,a more comprehensive index system is constructed.At the same time,a practical calculation method that can calculate all the indexes simultaneously is designed.The main research work is as follows:Firstly,based on the introduction of the basic concepts of peak regulation,the methods of peak regulation,peak regulation costs,and priorities of current different types of power sources are analyzed.Then,according to the new situation of more and more the unconventional regulation capacity taking part in peak balance,a new idea of peak regulation analysis considering unconventional regulation capacity is proposed,and the applicability of the existing peak-margin indicators and evaluation methods when considering unconventional regulation capacity is analyzed.To characterize the peak regulation balance when considering unconventional regulation capacity,based on the objective reality that the peak regulation is always balanced during actual operation,two new indicators,i.e.peak regulation output rate of condensing power unit and peak regulation cost,are proposed;Together with the original indicators,an index system that can comprehensively reflect the situation of the provincial power grid peak regulation from different aspects has been constructed;based on the traditional idea of peak regulation balance,a practical calculation method that can calculate multiple evaluation indicators simultaneously is designed for provincial power grids with AC-DC connection lines and complex power supply structures,and a calculation mathematical model is constructed.Based on the above index system and calculation methods,the peak regulation situation of a provincial power grid during 2016-2020 is evaluated.The validity of the method can be demonstrated by comparing the calculation result with the actual occurrence.And the analysis result of the future years quantifies the severity of the future peak regulation situation.Especially after the UHVDC full-power operation in 2018,if no measure taken by the system,it is difficult to guarantee the peak regualtion balance even if the unconventional regulation is used.Further,the examples analyze the reasons for the difficulties in peak regulation,and five strategies to alleviate the peak regulation problems for optimizing reserve,DC peak regulation,postponing power supply construction,PHS construction and thermoelectric reconstruction are proposed,and the effectiveness of the strategies are evaluated.The results show that a single strategy is difficult to effectively solve the problem of peak regulation of the provincial network,and the comprehensive application of the five strategies may be a better solution.This study will not only provide a comprehensive and accurate quantitative analysis index for the evaluation of provincial grid peak regulaion situation,but also provide an effective analysis method for analyzing the effect of peak regulation strategy.It has very good practical value. |
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